It has previously been proposed to so arrange printing cylinders on a printing machine that, respectively, prime-and-verso or double prime printing is possible. One such arrangement is shown in German Pat. No. 28 44 418. An impression cylinder is used which is of double diameter with respect to the cylinders of two blanket cylinder - plate cylinder couples. The machine is so arranged that the respective couples can be placed in circumferential engagement, individually, on the double-sized impression cylinder. Each one of the blanket cylinders, thus, with respect to the common impression cylinders, has two positions, namely an engaged and a removed position.
German Pat. No. 1,238,929 describes a customary, now well known five-cylinder printing system which has a common impression cylinder and two blanket cylinder - plate cylinder couples. One of the blanket cylinders can be shifted through three axial positions. The printing system does not permit, however, exchange of a plate during operation of the machine. In this system, it is not possible to selectively engage a blanket cylinder on the impression cylinder while the machine is operating.
German Utility Model No. 1,827,845 describes--particularly in FIGS. 3 and 4--a printing machine arrangement in which a web can be selectively printed either with double prime printing or prime-and-verso printing.